How to use ajax to call a boolean web method

[WebMethod]
     public Boolean Login(string uname, string password)
     {


         if (ValidateUser(uname, password))
         {
             FormsAuthentication.Authenticate(uname, password);
             return true;
         }
         return false;
     }

$(document).ready(function () {
       $('#btnLogin').click(function () {
           var username = "test"
           var password = "1234"
           $.ajax({
               type: "POST",
               contentType: "application/json; charset=utf-8",
               url: "wsLogin.asmx/Login",
               data: "{uname: '" + username + "'" + ",pwd: '" + password + "' }",
               dataType: "Json",
               success: function (success) {

                   alert("Boolean True");
               },
               error: function (error) {

                   alert("Boolean False");
               }
           });
       });
   });